Genre
- Anecdotes 1 canlyniadau
- Bibliography 4 canlyniadau
- Biography 2 canlyniadau
- Caricatures and cartoons 1 canlyniadau
- Case studies 3 canlyniadau
- Congresses 44 canlyniadau
- Forecasts 2 canlyniadau
- Handbooks, manuals, etc 1 canlyniadau
- Juvenile literature 3 canlyniadau
- Periodicals 27 canlyniadau
- Personal narratives 1 canlyniadau
- Platforms 15 canlyniadau
- Problems, exercises, etc 1 canlyniadau
- Statistics 7 canlyniadau